Metrology and GD&T Employee Evaluation Test

C

cpbraun

I have four candidates applying for a quality inspector position. Does anyone have a written quiz/test to evaluate GD&T and/or metrology knowledge? I could put one together but time is short. Any assistance would be greatly appreciated...
Thanks!
Chris Braun
 
S

Sturmkind

If you have a drawing with GD&T simply number a few features and ask for explanation / calculation (modifier calc. like MMC, LMC). Some general questions:

Q-What is hysteresis and why is it important in uncertainty measurement?
A Inability to repeat zero (or equivalent); inflates uncertainty.

Q-Most common GRR assumption error?
A Samples measured do not span range of expected production variation
A Failure to evaluate results for points that exceed the UCL Range.

Q Quickest way to determine integrity of measurement tool datum?
Ex: Calipers, 0-1" micrometer, etc.
A Clean, close, hold to light to look for wear between fixed and movable surfaces: Micrometer anvil to spindle for example.

I have some at home, but none other that are immediately available.

I hope this helps!
 
D

DrM2u

I would also suggest referring to the ASQ's body of knowledge for Certified Quality Technician, QCI's CQT Primer and other related mateials. You should design your test based on your needs and expectations related to the position in order to ensure that you select the most qualified candidate. Of course, there are also some human factors that come into play and worth considering. :)
 
S

Sturmkind

Oh, also if you do manual layouts:

Q What is cosine error and what is it's effect on results for an OD & ID cylinder measurement.
A1 -Not presenting indicator tip to work as parallel as possible causes OD's to be reported as too big, ID's as too small when rotated within a precision rotary jig.
A2 Quantifiable as the cosign of the actual observed presentation angle.

Q How can cosine error be mitigated?
A Use a teardrop shaped indicator tip.
 
C

cpbraun

Great Idea... I will look through their sample questions... Thanks!
 
C

cpbraun

Thanks for the info... these are some great topics. I've been doing playout of turbine blades for about eight years and I find it getting more and more difficult to find people who understand both layout and CMM methodology
 
D

DrM2u

You might want to look outside your industry for similar knowledge. Automotive, aerospace, medical devices, appliances, etc all use inspection and metrology to one degree or another. After all, it is a good market for employers to pick from. ;)
 

Stijloor

Leader
Super Moderator
Thanks for the info... these are some great topics. I've been doing playout of turbine blades for about eight years and I find it getting more and more difficult to find people who understand both layout and CMM methodology

Smart organizations have a training program (apprenticeship anyone?) and develop their own talent.

Stijloor.
 
C

cpbraun

Thanks, I suppose, for the input. Perhaps a full understanding of the situation would be useful in future evaluations...
 

Hershal

Metrologist-Auditor
Trusted Information Resource
For inspector, do not generally expect a metrology professional, especially in this economy. But ask about uncertatinty. If they know that it is a mathematical description of errors of a given measurement, then that is good. If you get a deer in the headlights look then you may want to review others first. Maybe come back to them but review others first.

Do what dentists call a working interview. Give them a part and drawing and have them inspect.

Ask what standards they have been involved with and in what roles. ISO9001, TL-9000, ISO 14001, ISO/IEC 17025:2005, ISO/IEC 17020, or similar.

Hope this helps.
 
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